Darryl Licht said:
Google and download ophcrack live cd! It creates a bootdisk that uses brute force to crack your passwords!
The OP has probably moved on to other issues by now

As a suggestion, it invites bad computer karma to assist in any type of activity or method which would seek to bypass security. As difficult as it is to watch the suffering of a fellow enthusiast, and as much as you know you can probably suggest a way to work around that security barrier - don't.

You can never tell whether they really are who they pretend to be, and whether their story is true, and that is in no way meant to refer to this OP specifically. If I was trying to get somebody to help me gain admin rights on a stolen system, I'd most likely start off my plea in a rather innocent tone...

"HELP! My college exams are next week, and all my work is on this machine, and I've forgotten the only admin account password, and I simply cannot pass without my notes, and my parents will disown me if I fail, and ... and I think I'm going to cryyyy if you're too cruel to help me!!!! (BTW, I'm a chick, just so you know, and I usually call myself 'Mandy21'.)"

The guideline is simple: no assistance granted or offered on any attempt to bypass security. If they don't know the password(s), they can reinstall the OS and start again. It's instructive anyway.